Pubic symphysis dysfunction (PSD) is a clinically variable condition within the spectrum of pregnancy-related pelvic girdle pain. Modern diagnostics should integrate clinical, functional, and imaging assessments. A diagnostic strategy for PSD in pregnant women was developed, incorporating clinical, functional, and ultrasound evaluation.

The clinical and functional analysis included 35 pregnant women with PSD and 70 pregnant women without PSD. Medical history, socio-demographic data, and the Pregnancy Mobility Index (PMI) were evaluated. The ultrasound protocol included measuring the superior and inferior symphyseal gap widths, interpubic disc morphometry, assessing hypo- and hyperechoic changes, and measuring the thickness of the superior and anterior pubic ligaments. A composite structural-ligamentous index of the pubic symphysis (SLI4; 0–4 points) comprised four ultrasound features.

Socio-demographic and reproductive characteristics did not reliably distinguish pregnant women with PSD from those without PSD. The most pronounced differences were found in clinical and functional parameters. Pain when turning in bed was reported by 80.0% of patients with PSD, when climbing stairs by 71.4%, and when walking by 62.9%. Contracted pelvis forms were noted in 14.3% of pain-free pregnant women and 40.0% of those with pain. Ultrasound revealed significant differences in morphometric and structural parameters of the pubic symphysis: superior gap width (p = 0.028) and superior pubic ligament thickness (p < 0.001). Hypoechoic foci in the interpubic disc were detected in 33.3% and 80.0% of women, respectively. SLI4 should be considered an echographic stratification tool for in-depth evaluation and dynamic follow-up.

A four-tier diagnostic strategy is proposed: 1. First-line clinical and functional assessment using PMI and load-dependent symptoms. 2. Ultrasound examination covering symphyseal gap width, the interpubic disc, and pubic ligaments. 3. Correlation of clinical and sonographic phenotypes for asymptomatic structural changes. 4. Application of SLI4 as a promising tool for structural-ligamentous phenotyping and patient stratification.

Elizaveta Nikolaevna Shlapak is a 5th-year medical student at the Faculty of General Medicine at the Medical University “REAVIZ” (227 Chapaeva St., Samara, 443001, Russia). She is actively involved in clinical and scientific research in the field of obstetrics, gynecology, and ultrasound diagnostics. To date, she has authored 5 scientific publications.